cli

Kind of a flag: controls whether a value is required and how it is checked.

Str is the default because it is what most flags are (11 of the compiler's 19). Bool needs no value: presence alone sets "true". Int is a Str whose value must parse as an integer, so a typo'd number is caught at the boundary instead of being silently clamped by the caller.

One accepted value of an enumerated flag, with the line documenting it.

A flag whose values is non-empty accepts nothing else: the parser rejects an unlisted value on its own and names the accepted set, so the validation, the error message and the help all read from this one array.

Specification of a single recognised flag. Pass an array of these to parse.

Everything a help renderer or an error message needs lives here, so the spec table is the only place a flag is described. A field left empty is a spec defect, not a feature: there are no undocumented flags.

What an action does with positionals past the first: drives its usage line and the error it raises on an unexpected one.

One action of the CLI: vader <name> <options>.

Parser output. flags carries every recognised flag's literal string value (bool flags resolve to "true"). positionals holds the tokens from the zone close onward, in order and uninspected. errors lists unknown flags, missing values and rejected enumerated values: non-fatal here; the caller decides whether to bail out.

A key the prompts understand. Anything else decodes to .Unknown and is ignored rather than guessed at.

One decoded keypress.

A keypress plus how many bytes it took, so the caller can decode the rest of the burst.

Why a prompt produced no answer.

A prompt that produced no answer, and why.

One option of a select or a multiselect.

Parse args against specs, stopping at the first positional or --.

One pass, no state kept between calls. Unknown flags inside the option zone are errors, not positionals: that is the whole point of having a zone, and it is what lets a mistyped flag be caught instead of silently becoming a filename.

True iff name was seen as a bool flag (or set explicitly to "true"). Missing flag → false, no error.

Read a string flag, falling back to default when absent.

Read an Int flag, falling back to default when absent.

The value is already known to parse (parse rejected it otherwise) so this cannot fail. It still falls back on an unparseable value rather than trapping, for the case a caller reads an Int flag from a ParsedArgs it never checked errors on. Range limits stay the caller's: --parallel wants ≥ 1, which is its business, not the parser's.

Render the overview: usage line, the action list, the common options.

Deliberately does NOT list every action's own flags: that is what render_command_help is for. A single flat help is how the hand-written one reached sixty lines.

Render one action in full: its usage line, then every flag it accepts.

This is the view a hand-written help can't give: vader build --help had no answer at all before, which is most of why the overview grew to carry every flag of every action.

Render the help of a program that takes no action: its usage line, then every flag it accepts.

Decode the first keypress in burst, starting at byte from.

Decode a whole burst into the presses it holds.

Open a session of prompts under title: the top of the rail every later step hangs from. Close it with outro or cancel.

Put an answered step of title on the rail, with lines under it: what a command did once the prompts were answered.

Close the session on message: what to do next, say.

Close the session on why nothing was done, on the error output.

Cut s to width columns, marking the cut so a truncated option does not read as a complete one.

Ask the user to pick one of choices; the first is chosen until the user moves.

Ask the user to check any number of choices.

The indices set in checked, in order.

Ask a yes/no question. Enter takes default_yes until the user switches it.

How one press answers a yes/no, or null when it decides nothing. Pure, so the accepted spellings are pinned by a test rather than by trying them.

Ask for one line of text.

Supports typing, Backspace, and Enter. There is no cursor movement inside the line: a prompt is not an editor, and the keys that would be needed for it (Left/Right plus a render that positions the cursor) are what would turn this into one.

Drop the last CHARACTER of s, not its last byte, so backspacing over a multi-byte character removes the whole thing.